Десериализация в JSON

public class RandomTest {
    public static void main(String[] args) throws IOException {
        String jsonString = "{\"data_coin\": {\"last_price\": 23183.57,\"last_change\": -0.57,}}";

        StringReader reader = new StringReader(jsonString);
        ObjectMapper mapper = new ObjectMapper();
        Bitcoin bitcoin = mapper.readValue(reader, Bitcoin.class);
        System.out.println(bitcoin.data_coin);
    }
}

@JsonAutoDetect
class Bitcoin {
    public List<Data> data_coin;

    public Bitcoin() {
    }
    @JsonAutoDetect
    class Data {
        public double last_price;
        public double last_change;
        public Data() {
        }
    }
}